Intermittent DOCSIS T4 timeouts causing confirmed internet outages

Minus 10dB is too weak / low, and it may be intermittently fluctuating even lower out of spec. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In an effort to try to obtain better connectivity / more wiggle room, check to see if there are any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/reconfigured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage from Home Depot, Target, Wal-Mart, etc. Splitters should be swapped with known to be good / new ones to test.

Also, check the coax cable for any damage such as cuts, nicks, abrasions, kinks, sharp bends, or animal chews.

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two-way splitter connected directly off of the drop from the street / pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

Good luck with it !

Hey there, @appario, thanks for reaching out through Xfinity Forums regarding your internet connection. I can understand wanting this escalated, especially since you’ve already had a technician replace components and captured a T4 timeout at the same time as the service interruption. The modem logs and recurring disconnects are helpful details. We would be happy to take a look at the connection. Can you please send us a direct message with your full name and your full address? 

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